1. Field
The present inventive concept relates to electronic devices, and more particularly, to nonvolatile memory devices including a buffer ram and boot code management methods thereof.
2. Description of the Related Art
Generally, a semiconductor memory is the most necessary micro electronic device in a digital logic design, such as a computer, and in applications using microprocessors ranging from satellites to consumer electronic techniques. Thus, development of a technique for manufacturing a semiconductor memory including a process improvement and a technical development obtained through scaling for a high integration and a high speed is helpful in establishing a performance standard of other digital logic systems.
Semiconductor memory devices are classified into volatile semiconductor memory devices and nonvolatile semiconductor memory devices. Nonvolatile semiconductor memory devices can store data even when their power supplies are interrupted. Data stored in nonvolatile semiconductor memory devices may be permanent or reprogrammable according to a memory manufacturing technique. Nonvolatile semiconductor memory devices are used to store a program and a micro code in a wide range of applications such as in computers, in avionics, in communications and in a consumer electronics industry.
A typical nonvolatile memory device may be a flash memory device. A NAND-type nonvolatile memory device has an advantage of high integration and high capacity. Due to this advantage, use of NAND-type nonvolatile memory devices has been increasing rapidly in applications for mobile systems and various kinds of application systems. However, the NAND-type nonvolatile memory device has a disadvantage in that a time required by the NAND-type nonvolatile memory device to read and write data is slightly longer than for a RAM. This disadvantage affects performance of a system fitted with a nonvolatile memory device. One fusion memory which makes up for the disadvantage and makes use of the advantage is a oneNAND flash memory device. The oneNAND flash memory device has an input/output protocol of a NOR-type flash memory (or SRAM). The oneNAND flash memory device includes a NAND-type flash memory core suitable for high integration, a high speed buffer RAM, a high speed register and an error correction to embody a more advanced memory performance with high capacity, high speed and high stability.